I understand a lot of engineering went into making that & needs to be recouped, but it still sounds on the high side. I wonder how hard it'd be to build one, if required.
Might depend on what he means by "power supply". For a purely electrical thing it does sound expensive unless there is a stringent low-noise requirement (which would surprise me in an industrial laser).
The lasers I've heard of work by amplifying light along a fibre that has been energised by some other light source -- and that light source is sometimes also a laser. So in this case the "power supply" might actually be thing that produces 10-20kW of light (of which only some is converted into laser light along the fibre).
OP here. by power supply, I was talking about the metal box that the bright light comes out of. The thing making the 4kw of laser juice. Not just a transformer.
Not really given the highly integrated nature of laser manufacturers where they bundle the table, drives, CNC, material handling, power supply, and (often) SLA together. Additionally there is a lower run-rate of consumables in comparison to other industrial cutting technologies so the life-time cost is more comparable to competing technologies.
So why not always use laser? They have far higher upfront costs as their business model is not consumable-driven. Further they are limited in material thickness and finish they can handle. They are great at cutting sheet and thin (<= 1/4") metals, when the surface is clean and uniform as mentioned above, but if your shop needs the ability to cut thicker materials or the up-front cost is too high then plasma, oxy-fuel, or (possibly) waterjet are better options.
The lasers I've heard of work by amplifying light along a fibre that has been energised by some other light source -- and that light source is sometimes also a laser. So in this case the "power supply" might actually be thing that produces 10-20kW of light (of which only some is converted into laser light along the fibre).